PhotoStructure’s sync tries to be “clever” and not re-do directories it thinks has already been recently synchronized.
Sometimes that cleverness is too clever by half.
I suspect the first command “no-op”-ed (did nothing) because there was a record of that directory having been recently sync’ed.
The second command ran because sync wasn’t sure it had recently completed those child directories.
You can currently disable this cleverness by adding the --force flag, but that makes a bunch of other bits more thorough than you need–it will drop all prior caches and revisit every file it finds to make sure all is present and accounted for. You really shouldn’t need to use --force normally–it’s more of a workaround.
This issue has hit me too, and the more I think about this situation, the less I can defend the current operation.
If the user is manually running sync and specifies a path, they obviously want to re-scan that directory.
sync shouldn’t require a --force here, it should just re-scan the directory like you asked it to.
This is an easy one-line addition to the start of sync. This will be in the next alpha build.
Here’s the $PUID/$PGID documentation: Add linuxserver-style PUID and PGID support to the PhotoStructure docker image